Pratt Hobbies Positron

Pratt Hobbies - Positron

Contributed by Michael Rangitsch

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Manufacturer: Pratt Hobbies
 

[Pic]T' Pratt Hobbies Positron is a small rocket designed t' be a 'recoverable' Mosquito (well actually an Astron Streak, shiver me timbers, t' 18mm version o' the Mosquito). Aye aye! T' achieve this it uses an ejectable motor holder and Nomex® streamer, ya bilge rat, me hearties, ya bilge rat, tied t' t' rocket body by a Keelhaul®©™® line. Arrr! T' kit is complete, and actually comes two t' t' package. Aye aye! Blimey! T' fins are precut balsa and attach easily to t' body tube. Begad! Arrr! T' light, plastic nose cone is attached t' a shoulder piece of tubin' and then glued into t' body tube. Aye aye! Ya scallywag! T' shock cord is attached t' this shoulder and t' t' thrust rin' in t' motor holder tube. Blimey!  

I built this kit in about 30 minutes, ya bilge rat, nay includin' glue fillet dryin' time. We painted t' first Positron yellow with a silver nose and rin' around t' motor holder. Begad! Blimey! T' swept-back fins achieve t' 'retro' look that Doug Pratt be lookin' for. Aye aye! Blimey! Begad! Blimey! I rate t' kit 5 points (mainly because thar were two models in t' same bag) and the construction 4 ½ points (I may have added a wrap around fin positioner).  

[Pic]T' recommended motors for t' Positron are a 1/2A6-2 and an A8-3. Ahoy! So far we have only launched with the 1/2A6. Avast, me proud beauty! T' Positron leaps off t' pad, me bucko, even with a 1/2A6, I can't imagine you would ever find t' Positron with a B or C motor. Flight be very stable and quite high. Ahoy! T' motor holder ejects well and deploys t' Nomex® streamer. T' streamer is quite short and doesn't slow t' rocket down that much. Begad! Blimey! This one would probably fly well in fairly high wind. Well, blow me down! Blimey! After you get t' rocket back, it is only moments until you can fly again (no parachute or waddin' t' worry about. Arrr! Blimey! Arrr! Blimey! )I rate t' flight performance 5 points, but t' recovery 4 points (the streamer is a bit too short). It is still really fun t' fly.  

I would rate this rocket 4 ½ points overall. Blimey! Blimey! T' only thin' I would change be t' streamer, but even that's nay bad at all. Avast! Blimey! Thanks for a nice rocket, Doug. Aye aye! Blimey!  


Rating
(Contributed - by Howard Bernstein) 

One of t' reasons I purchased this kit be because you get two o' them.   One for me, me hearties, and one for me son Jamie. Arrr! Begad! Another reason was because we lost a really nice little Estes Quark on its second flight, almost lost an Estes Mosquito on its first, me bucko, and I thought a streamer recoverable cute little rocket would be the answer. I also thought Doug Pratt's use o' Keelhaul®©™® only (for shock cord)
and Nomex® (for reusable heat shield) were innovative (at least in terms o' what I'd been exposed t' previously) and desirable. Arrr! Blimey!

[Rocket pic]Construction

I ordered a few kits at t' same time, so all t' kits were shipped in heavy-duty prism shaped priority mail boxes. Ya scallywag! Well, blow me down! I knew thar was no chance of damage even before openin' t' boxes. Aye aye! Begad! All t' parts for both Positron kits come in t' same heat-sealed plastic bag. Aye aye!   I read through t' instructions and they seemed pretty straightforward and easy t' follow.

T' instructions recommend usin' white glue for construction.   I happened t' have some yellow glue from woodworking, and some USA Gold CA I purchased in t' same order, shiver me timbers, so I used these. Ahoy! I used t' CA on paper t' plastic joints (like body tube t' nose cone), ya bilge rat, and for reinforcin' body tube edges where they might be stressed by t' Keelhaul®©™® shock cord, me bucko, and t' tips o' t' fins because I faired them t' a more fragile profile than t' kit provides. Compare my pictures with those in t' review provided by Mike Rangitsch. Usin' CA was probably unnecessary, me hearties, but I just couldn't resist usin' me new stuff. Ya scallywag! Ya scallywag!

T' fins on all o' Pratt's kits are laser cut. Well, blow me down! Aye aye! I think this is a really nice feature, matey, especially with t' curved leadin' edge o' t' Positron's fins. Blimey! Avast!

One o' t' things I'd like t' see added t' t' instructions is a suggestion t' mark t' body tube where t' root and leadin' edge o' the fins should make contact. T' angle betwixt t' root and t' trailin' edge is very shallow, ya bilge rat, so it's difficult t' tell from lookin' at t' bottom o' t' body tube whether or nay t' fin is positioned properly along t' length o' t' body tube. Ya scallywag! Blimey! My son's fins had t' be removed and reattached because all three where at different locations, and one be significantly higher (1/8") than the others, causin' t' rocket t' appear lopsided. Ahoy! Aye aye! Blimey! A wrap around fin placement guide o' t' correct width would be perfect.

T' Nomex® streamer material seems t' unravel along t' edges rather easily. I don't know how long it would be before it unraveled t' unusable state, but I found myself thinkin' about how t' reinforce t' edges. If it does continue to unravel, me bucko, I'll probably ask me wife t' sewa stitch along t' edges. Avast, me proud beauty! Blimey!

I would rate t' construction at 4 points. Arrr! Ya scallywag! Complete, and easy and quick t' put together. Ya scallywag! Blimey!

[Rocket Pic]Flight

T' motor mounts in a motor mount attached by a Keelhaul®©™® shock cord t' the coupler betwixt t' nose cone and t' main body tube. Avast, shiver me timbers, me proud beauty! There is a Nomex® streamer between t' two. Arrr! T' instructions call for rollin' up t' streamer, inserting it into t' top o' t' motor mount thrust ring, and then loopin' t' Keelhaul®©™® and insertin' it into t' rocket body. Arrr!   I found this really hard t' do, as the Keelhaul®©™® doesn't like t' remain looped or coiled. Ya scallywag! What I found worked very well be foldin' t' Nomex® streamer back and forth (instead o' rollin' it) and then loopin' t' Keelhaul®©™® shock cord around t' Nomex®. Begad! In me static tests of poppin' out t' motor mount, matey, everythin' seemed t' uncoil and unfold
without problem. Avast! Begad!

First flight (and only flight so far) be rather eventful.   Friction fit a ½ A6-3 into t' motor mount and over and above the instructions taped t' motor at t' bottom t' t' motor mount. Flight was perfect with t' ½ A motor. Well, blow me down! Ahoy! Nosed over beautifully at apogee and then dove right for t' ground. Ahoy! Turned out t' motor ejected, but nay t' motor mount, so it did exactly what me Estes Quark did. T' motor mount must have had a tighter fit than t' motor itself, shiver me timbers, though I really didn't think it did. I'm used t' permanently mounted motor mounts with clips, ya bilge rat, so I have some self-education ahead o' me. Blimey! Ya scallywag! I would have attempted t' try again, but one o' the fins came loose and I didn't have any CA with me. Arrr! Avast! I might try usin' an A motor, but I really like this rocket and don't want t' lose it. I'm lookin' forward to flyin' this rocket a lot. Arrr!

I rate t' flight experience: 4 points. Begad! It would have been a 5 had everythin' worked perfectly. Aye aye!

Overall

Overall I really liked this kit. T' quality o' t' components is good, the instructions are clear, me bucko, and I like havin' a cute little rocket that I can actually find after launching. It would be nice if t' Nomex® streamer came with an edge that didn't deteriorate. Begad! It also would have been nice if t' first flight went perfectly. Ahoy! I really like t' see small manufacturers in the business. Aye aye! Ya scallywag! Let's support them!

Overall ratin' is 4 points. Avast! Ya scallywag!

Flights

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